Various members of the NORFANZ team kept a diary of their experiences over the four-week voyage. You can read about their experiences below.
Day 22: 31 May 2003
By Mark Norman, Museum Victoria
Low swell (2 m), 16 knot S wind, 18 °C
It’s 10.30 am and we’re currently headed towards Reinga Bank. It’s about 10 hours steaming so we’re using the time to catch up on everything. We’ve had a very good run with suitable seafloor for sampling and had very few gear problems, compared with the difficulties of very rocky ground in the first leg of the cruise. We are returning to rockier ground now, so will be relying heavily on the seabed mapping team for choice of locations.
The list of new species and new distributional records are getting very impressive. So far the voyage has collected samples and records of more than 500 fish species and over 1100 invertebrate species. The diversity in forms and adaptations is fantastic. Researchers onboard are starting to tally the total number of new discoveries. Many of the new distributional records are for species that have rarely been sampled. Last night’s trawls provide a good example.
A ratcatcher trawl around midnight brought up a large number of slimy slickheads (Rouleina attrita) and a total of 14 rattail species in a single catch. According to the identification literature on board, at least one and possibly two of these species are new to science. The catch included another slickhead species, a Norman ’s Snothead (Mirognathus normani), which seems particularly appropriate as I have the cold that is currently roaming the ship. The most exciting find in this haul, one that sent Andrew Stewart of Te Papa into convulsions, was a very rare anglerfish known as a Mossfish.
At 4 am this morning we did the last ratcatcher trawl for the Wanganella Bank. It sampled at 900 m and mainly caught small sharks. It also closed the book on the long saga of the “Enigma Skate”.
Twenty years ago, the original “Tangaroa” (since replaced by this ship) captured a strange small ray on the Wanganella Bank. It was a single female specimen of skate (sting-less rays) that was so different it was even unclear what group (genus) it belonged in. Adult male specimens are critical in identifying and describing sharks and rays. The male reproductive organs (especially the “claspers”) are one of the best diagnostic characters. At the time, Dr Peter Last, a shark and ray expert from CSIRO Marine Research, began the formal description necessary to name this distinctive skate, but a male was needed.
The problem is that the deep water in this corner of the planet is a long way from anywhere. Not many people poke around out here. The few commercial fishing boats that have fished out here are not particularly interested in little rays. No specimens surfaced in 20 long years. One of the tasks of the NORFANZ cruise was to return to the same location and see if the new “Tangaroa” could find better voucher specimens.
For the last two days we’ve been trawling in this region. It has been a fascinating area and has brought up many interesting animals. There was initial excitement as several female specimens of the “Enigma Skate” were caught. More excitement followed as two immature males came in. By the last trawl for the region last night, Peter still didn’t have his adult male. So a nervous group stood around the opening net at 4 am last night, waiting to see if an adult male would turn up. The catch contained some small sharks, a larger more familiar skate and a mix of rattails. Then suddenly there was a shout and a small skate was extracted from the pile. Peter confirmed it was an adult male. An adult female followed. The “Enigma Skate” could finally be named.
Taxonomy is the study of identifying and naming plants and animals (living or dead). It is not just stamp collecting (no slight intended against stamp collectors). Formal description of any species is important for a number of reasons. It is a universally agreed system for comparisons with other named and new species. It allows:
- development of identification tools
- generation of lists of fauna and flora for specific regions
- investigation of relationships between creatures, i.e. the study of food webs
- generation of information on biodiversity, rarity and conservation status
- investigation of the evolution of life on earth (and in the sea).
Sound taxonomy underpins all other branches of biological and conservation research. Without it, the rest are meaningless.
It’s 2 pm now and we’ve stopped to do a sound velocity probe, allowing the seabed mappers to calibrate their equipment as they constantly map the seafloor beneath us. Back to sampling tonight. More tomorrow.
Day 23: 1 June 2003
By Mark Norman, Museum Victoria
Low swell (1-2 m), 10 knot S wind, 17 °C
Well, we are on a seamount on the Reinga Bank and, as expected, it is a hard spiky rocky seafloor, not very net friendly. In these situations we revert to the old indestructible Sherman sled. It has been down twice overnight along with a single orange roughy trawl.
Sherman didn’t catch much on the first run but it certainly earned its keep on the second, bringing up a high diversity of small invertebrate species. After spending most of the night working up this catch, the night invertebrate team identified 96 species of invertebrates, of which more than 40 species were first records for the voyage. So it was a very busy night of careful sorting (with fine tweezers), looking up identification keys, and documenting and photographing all the new material. The seafloor on the top of this rocky seamount is made up of rock and rubble beds, supporting a rich invertebrate fauna. Seamounts can often support much richer communities than the surrounding deep-sea slopes and plains. This is caused by the nature of water flow over seamounts. As currents move across the seafloor and bump into a seamount, eddies and currents form that can concentrate nutrients and draw them up towards the surface. This is sometimes called a “Taylor’s Column”. This mixing of cooler, nutrient-rich water with slightly warmer shallower layers is very productive and can support rich marine life. Once you add rocky surfaces for invertebrates to attach to, these environments can end up supporting large animal communities. Sherman appears to have sampled one of these last night.
People usually associate corals with shallow tropical waters, but the deep sea is also home to many types of corals. Shallow water corals (like those found on the Great Barrier Reef) get most of their food from sunlight by nurturing small plant cells (called zooxanthellae) within their tissues. The plant cells produce sugars by photosynthesis in return for a safe place to live. Around 95% of a shallow-water corals food comes from these plant cells. In the deep sea it is different. There is not the sunlight so there is no way to gain nutrients from symbiotic plant cells. Deep-sea corals must use their stinging tentacles to catch small animals or feed on the rain of fine organic matter that filters down from the surface. Perhaps due to the low food levels in the deep sea, many corals are very long-lived.
The rocky seafloor at the Reinga Bank site last night seemed ideal for corals and many different types were found. These included species of black coral, several bamboo corals (named for the regular dark bands along the coral stem that make them look like bamboo), octocorals (named after the eight tentacles on each polyp), fan corals (also known as “gorgonians”) and a few solitary corals. There were also pieces of coral rubble from several hard coral colonies (“scleractinians”), showing that these coral types also occur in the area. In turn, the corals are home to many free-living invertebrates. The crustaceans in last night’s catch included many new species of squat lobster, small crabs, shrimps and hermit crabs. One rare find was four animals of a sponge-dwelling shrimp in the family Spongicolidae. This deep-water family of shrimps is very poorly known. It is a rare event to get a single specimen, let alone four. Other groups included snails, serpent stars, slate urchins and sea stars. Coral colonies can also support anchored invertebrates (known as “sessile” animals), such as stalked barnacles.
But by far the most common species in this catch was a new species of brittle star (Ophiacantha sp.) that came up in its thousands. We ended up with three fish bins of these tiny stars. The densities of this species are obviously very high .
An orange roughy trawl has just come up from around 1000 m deep. It mainly contained very slimy slickheads , as well as several species of chimaera, rattail and basketwork eels. There was also a single snipe eel and a viperfish. Meanwhile, the Sherman has come up with a pile of rocks and about three squashed prawns. It has just gone out again.
Lots of birds behind the ship today, mainly Cape Petrels and shearwaters but also a Wandering Albatross and what look like two Grey-headed Albatrosses.
Day 24: 2 June 2003
By Mark Norman, Museum Victoria
Low swell (1 m), 10 knot NW wind, 18 °C
Big afternoon and evening yesterday. Returning to the area of the million brittle stars, a Sherman sled, an orange roughy trawl and a beam trawl were sent down at different depths. The sled was on the slope, at around 700 metres (170 m deeper than yesterday’s live brittle star aggregations). It seemed to be where all the shells and other hard remains slid down to when they die. There were very few live animals in the shell gravel collected in this trawl. The next two nets were shallower and brought up more interesting creatures, again mainly invertebrates. It took the night invertebrate crew another six hours to sort this catch, identifying more than 80 species. One of the weirdest was a large sponge that looked like a cross between a bush and a large whale bone. Crabs, shrimps and serpent stars were living in its nooks and crannies.
Fish catches have also been interesting, including a long-finned gemfish (Rexea antefurcata), a prickly shark, a leopard chimaera (Chimaera panthera), red dory (Cyttopsis roseus), mirror dory (Zenopsis nebulosus) and New Zealand frostfish (Lepidopus caudatus). The stomach of one frostfish contained a small deep-sea cardinalfish that was named after Lord Howe Island (Howella sherboni). This catch also included a few Richardson ’s Boarfish (Pseudopentaceros richardsoni), a species that has been found to congregate around seamounts in large numbers and has been heavily fished in the past.
Becoming a regular theme on this trip, yesterday saw a dramatic increase in the world’s collections of another rarely caught fish. The small rattail fish, Caelorinchus cylindricus, was recently described from New Caledonia by Tomio Iwamoto (who is on board) on the basis of a single animal. In one day of sampling, the world tally has now risen to nine specimens. These extra specimens will be distributed amongst the reference collections of the organizations represented on board.
What happens to all these collected invertebrates and fishes? Are they of any value? Or do they just get rammed in some basement and forgotten? The answer to the last question is a definite “no”. These specimens are of enormous value. All are preserved and transported to government museums and reference collections where all are identified, catalogued, assigned registration numbers and stored in accessible climate-controlled research collections. Where necessary, specimens are loaned to experts around the world to get material identified. Museum and research collections house, curate and do active research on these valuable voucher specimens.
These reference collections play many important roles, most of which are not seen by the general public. These include being:
- A repository for the actual specimens to which new names are formally attached (known as “type specimens”).
- A reference collection for studies on biodiversity, conservation, human impacts, ecology and evolution.
- An aid to species identification s for customs, quarantine, fisheries, the seafood industry, pest control and studies of introduced species.
- Specimens and information for public education programs, publications, exhibitions and displays.
These collections also provide a snapshot in time. If things like climate change have a major impact on life in our seas, it will be data from museum collections that will allow it to be detected. The aim of these collections is to keep these specimens and all their associated information, images and tissue samples in good accessible condition, for ever. Because of museum collections, many of the animals on which Darwin based his theory of evolution are still intact today. So are other specimens dating back to the middle ages. Museums house the only remains of the Tasmanian Tiger, the Dodo, the Flightless Auk and the Stellar Sea Cow, as well as many other recently extinct animals.
So a dead fish is not just a dead fish. It provides information on many things. All this information is critical for sound management of natural systems.
Back to the voyage. There was another long steam overnight and now the sound velocity probe has just gone down in 1200 m of water to allow the seabed mappers to calibrate the multibeam scanner. Then we can choose appropriate ground to sample.
The choice of sites is a collaborative effort between the voyage leader, scientific staff, shift leaders, multibeam mappers and the captain or mate. Scan maps are generated, rock hardness is assessed and flat ground is sought. Sample sites are chosen at a range of set depth levels and appropriate sampling gear is selected. The deck crew deploy the nets on the say of the captain or mate, and transponders on the net and doors show the exact position of the net underwater so that it can be set down accurately on the best ground.
An orange roughy net has just gone down. I’ll let you know tomorrow what it found.
Day 25: 3 June 2003
By Mark Norman, Museum Victoria
Low swell (1 m), 15 knot N wind, 18 °C
The sun is getting low in the west in the late afternoon and the weather has continued to be kind to us. Yesterday afternoon was again busy. First the orange roughy net came up with some interesting animals, some of which were a bit worse for wear because of a less welcome passenger, a seal shark . This shark is one of the cookie cutter sharks that manages to take perfect round holes out of anything within biting range. As a consequence, many of the animals in the catch had big chunks bitten out of them. This catch also included a different stone crab species, some great condition jewel squids and a new skate species, which is deep blue in colour.
The beam trawl went out next and came back absolutely packed with dead shells and coral rubble. The pile spread over the back deck and became a team effort to heave more than 20 fish bins full to the invertebrate sorting area. The night shift then spent four hours sifting through this pile, mainly extracting small crabs, shrimps, sea urchins, brittle stars and several large sea spiders.
The next beam trawl came up with several un-collapsed collapsible sea urchins (Phormosoma sp.) complete with poisonous spines, so they had to be handled carefully.
This morning’s ratcatcher at 4 am sampled down to 1.2 km deep and contained a rich mix of species including slickheads, rattails, small sharks, tripodfish, basketwork eels, snipe eels, another blobfish, viperfish, hatchetfish, orange roughy and a large chimaera. It also included a tiny long-nosed chimaera and two more of the new blue skates.
In many of our trawls we have been getting what look like big blobs of snot. They are generally torn up, but when you float out the intact ones in water you find that they are egg-shaped animals with an obvious gut and a star-shaped structure at one end. These are actually jelly-like sea cucumbers that swim (rather than crawl along the seafloor as their more muscular relatives do). The jelly-like flesh helps make the animal buoyant so that it can float along and descend to the seafloor to lick up any organic matter (“detritus”) that has settled on the mud. This buoyancy saves energy compared with living on the seafloor and trying to wade through fine soft mud. Saving energy is a common theme in the deep sea as food is scarce, so animals need to travel very efficiently. Many animals use jelly-like flesh to make themselves float or hang mid-water. Most of this jelly is made up of compounds called “glycosaminoglycans” that have a very low density. These compounds cancel out the weight of any muscles or hard structures. Some sluggish deep-sea fishes and squids use this jelly system of buoyancy.
Bruce Barker from CSIRO has been deploying the drop camera for the last couple of days, after he and the crew modified it to fit the Photo Sea camera system. He has developed the films and produced some dramatic images of the different habitat types that we have been sampling in this region. One on rocky ground shows a large fan coral (gorgonian) with other sessile animals (anemones and corals) attached. Another rocky ground shot has small fan corals and a fan sponge as well as a scorpionfish waiting for a feed. The camera also photographed the “million brittle star” site and showed why we caught so many. One photo of the muddy seafloor shows brittle stars spread evenly over the entire surface.
Until now there has been no mention of the most important people on this ship. Without their efforts, there would not be a single trawl, no specimens would be caught, identified, photographed or preserved. These people are the cooks, Kim Ashby and Yvonne French, and steward Dave Chapman who have been keeping us all very well fed and happy. The food has been excellent, possibly too excellent, as some on board head back for third helpings of dessert. Many thanks to these three people for all their efforts.
Day 26: 4 June 2003
By Mark Norman, Museum Victoria
Low swell (2 m), 22 knot NW wind, 18 °C
Another day, another skate. Last night brought in yet another new skate species, this time one with spines all over the underside, suggested as an adaptation for living on rough rocky ground. It is “species F” in a new genus of skates. Last night also saw a catch of large mature Richardson ’s boarfish off the top of a seamount. Seamounts often act as sites for large breeding aggregations of deep-water fishes. This has lead to very heavy commercial fishing of such aggregations and subsequent declines in species such as orange roughy . Last night also saw the first New Zealand record for a whole family of fishes (family Draconettidae) from one small fish in the genus Centrodraco.
The first catch of our shift was at 4 am this morning. It included small sharks, long-nosed chimaera, orange roughy, oreo dories, blobfish, basketwork eels, vomited squid (from the eels), a rarely caught pale blue slickhead (genus Leptoderma), long-legged crabs, another big red stone crab, prawns, blind lobsters, sea spiders, the ever-present sea urchins and large anemones.
The real revolution of this special collaborative voyage has been the rapid onboard generation of the detailed and extensive photo reference folders. These allow immediate recognition of species (named or new) that have already been encountered in the course of the voyage. Producing these folders has been a massive task. All the digital fish photographs have been taken by Robin McPhee of Te Papa and Australian Museum staff, Mark McGrouther (first leg) and Kerryn Parkinson (second leg). Photos go into a temporary folder for review by fish experts onboard and are then coded and placed in the final reference folders. So far four large fish volumes of detailed fish identification sheets have been produced for more than 500 fish species.
For the invertebrates, the even larger task (because of the higher diversity) has primarily been taken on by Karen Gowlett-Holmes of CSIRO, who has done an enormous amount of work to produce and keep up to date the invertebrate folders. She has been aided with the photography in the day shifts by Phil Alderslade (first leg) and me (second leg). At this stage of the trip, more than 1300 species worth of invertebrate identification sheets have been produced. Keeping these folders up to date can be a nightmare. Last night’s beam trawl brought in 114 species of invertebrates of which many are new additions. In one Sherman sled a few days ago there were 60 new species additions in a single catch. This means to keep the folders current, Karen has to edit up to 100 images (as some species need both wide and close-up shots), assign code numbers and print all the images. This is just for one sampling station.
Each different species recognised on this trip has been assigned a CAAB code (Codes for Australian Aquatic Biota). This code places animals in their family groups and assigns a unique number for each as a way of dealing with changing taxonomy (such as reviews of groups that change scientific names) or the delays and slow process of getting new species described. These codes are linked with collection information, images, specimens and tissue samples.
All the information generated on this trip is entered on to the onboard database. After a sample, the details of the sampling station are entered directly from the bridge. Catches are identified and data sheets are filled in by each group. These then go to Brent Wood and Neil Bagley who enter everything on the ship’s network, assisted by Malcolm Clark, Peter McMillan and Kevin Mackay. Data verification is critical as errors significantly weaken the value of this information. Any anomalies found on data sheets are checked back with the sources. The final print out is then compared to the original catch notes. The resulting data set allows immediate analysis and the capacity to generate all sorts of summaries, e.g., by species, by station, by depth, by gear, by location or by seamount. Maps such as the one shown can be generated by scientists on board for their particular groups, summarizing the locations and scale of catches for each station of the NORFANZ cruise. These maps are generated using public shareware from Generic Mapping Tools and Smith and Sandwell (satellite-derived seafloor bathymetry). The system is very efficient and at the end of NORFANZ, all participants are handed a CD with the full data set for the voyage.
The beam trawl came up at lunch time from 850 metres with sea urchins, sea stars, hundreds of miniscule white scallops, ribaldos, several coffinfish species and some rattails. A ratcatcher to around 800 m has just come up with a load of fish and nine spectacular small shrimp . More tomorrow for our last day of bottom trawling.
Day 27: 5 June 2003
By Mark Norman, Museum Victoria
Low swell (1-2 m), 10 knot NW wind, 17 °C
Last day of trawling today before the long steam towards Wellington. Overnight we’ve been on very rocky ground at around 800 m, so have had limited success in getting samples. The Sherman bounced around and didn’t catch much. The first orange roughy trawl snagged up immediately, the second came up with one shark, one silver roughy and three sea urchins. The last had little more, with a few rattails, a couple of sharks, slickheads and an orange roughy. We are now heading towards a much deeper site.
As time is running out, I am frustrated that there are still too many interesting stories of the deep-sea animals we’ve been coming across and their weird adaptations and behaviours. So I thought I’d briefly cover some of the more interesting ones.
The front ends of many deep-sea fishes are fascinating. The viperfish (Chauliodus sloani) has great wide jaws with huge teeth. They coax in their fish prey with a glowing lure on their head. When it comes to swallowing, their whole head is hinged: they have a flip-top head. They lift the head like the nose cone of a front-loading cargo plane and shunt the fish straight into the stomach. These fish hang in the water halfway between the depth limits of night migrating fishes and wait twice a day to ambush the passing traffic.
Many deep-sea fish will try to eat anything irrelevant of size. The Loosejaw (Malacosteus niger) can dislocate its long jaws to fit anything in, resetting them once the meal is inside. The Hammerjaw (Omosudis lowei) has a big solid lower jaw with strong teeth. It uses these to make fast strikes on passing squid.
The jaws of snipe eels (family Nemichthyidae) seem ridiculous. They are long and thin with small fine teeth, and both curve outwards. So they don’t even join up. It’s only when you look at their diet that you get some clues, they feed on shrimp. Some researchers have suggested that these fast eels thrash about and use their long beaks to tangle the long antennae of fast shrimps, which then can be easily grabbed.
Many deep-sea ambush predators have hinged teeth that can be flattened down when prey is going in and stand up when resisting. The deep-sea lizardfish has these sort of teeth, they don’t even need to actively swallow, the struggling prey just ratchets itself inside.
Some oreo dories have adaptations for eating stinging jellyfish. At the back of their throat the gill arches and gill rakers are modified to form a second set of grinding jaws, known as a “pharyngeal mill”. These break up the jellyfish and help discharge the stinging cells. As the bits are swallowed, the last of the stinging cells do no harm as the throat and oesophagus are lined with thick leathery skin.
Just like crows to a road kill, many animals of the deep sea are attracted to dead animals. Carcasses sinking from the surface is one of the ways energy flows from surface waters to the nutrient-poor deep sea. Of these carrion feeders, the most voracious are the large fast-swimming “amphipods” (relatives of the springtails you find under rotting seaweed on the beach). Some get to 18 cm long. They cruise like buzzards up to 20 m above the seafloor waiting to detect the smell of a fresh sinker (stinker?). They then swarm to the carcass and can strip a large animal in under 24 hours. These animals can eat more than 60% of their body weight in half an hour (the equivalent of us eating a whole sheep in half an hour!).
Swarms of smaller amphipods and other crustaceans (isopods and ostracods) also converge on carcasses. They end up being the desired food of some small jelly-like sluggish fishes like the snailfish (Psednos sp.) we caught several days ago. The jelly-like flesh gives buoyancy so these animals probably float around smelling for carcasses and then bob in and feast on the swarms of small crustaceans. Nobody knows how they avoid being eaten themselves at these feeding frenzies.
We just brought up the ratcatcher from 1700 metres with a fairly small catch but an amazing array of creatures, many seen for the first time on this voyage. In the invertebrates there were fluorescent orange lobsters new for the trip, large jelly-like finned octopuses, jewel squid, a jelly-like free-swimming octopus without fins (called Japetella), collapsible sea urchins, three large sea spiders (over 30 cm across) and a range of prawns. The fishes included a large blobfish, a large white skate that is at least a new species and may even be a new genus, chimaeras, deep-sea lizardfishes, an anglerfish, a halosaur, slickheads, a Schmidt’s cod (Lepidion schmidti) that only come in one size (big), and some rattail species new for the trip. There was also a weary fish, the first record of the genus Ahliesaurus from New Zealand waters, much further south than previously reported. It was clear that there was a very different fauna at these depths compared with our shallower trawls in the region.
The mid-water trawl has just gone out in deep water. More tomorrow.
Day 28: 6 June 2003
By Mark Norman, Museum Victoria
Increasing swell (2-3 m), 20 knot SW wind, 16 °C
Today everybody was able to sleep and wake at a more reasonable hour. As all sampling finished yesterday, everybody was able to get a solid night’s sleep. The Tangaroa crew and the scientific staff have all changed back to day shift. We are now on the long steam back to the ship’s home port, Wellington.
Yesterday’s mid-water trawl was very successful. The mid-water net is used for sampling the marine life of open water and is very different in set-up to the other nets we have been using. It still uses the doors (otter boards) to hold the net mouth open but has different wings and ground rope arrangement. The wings contain very little net, mainly consisting of long lengths of rope joined to make a large grid. Vibrations from these ropes are enough to flush corral fish and invertebrates into the net mouth. Floats hold up the head line of the net mouth while two large tangles of chains act as corner weights to hold open the bottom edge of the net mouth. The cod end of the net is fine mesh, good for sampling some of the smaller animals.
We deployed the net at 1700 m deep. As marine life is not very abundant in mid-water at these depths, this net was towed for more than an hour. It bought up only a small catch but contained fantastic animals. These included gulper eels , viperfish, several anglerfish species including Johnston’s anglerfish, lancetfishes (Alepisaurus brevirostris) with their upright sail fin, several small firefly squids (genus Abralia), two vampire squids , small transparent shrimp, twelve species of lanternfishes, two species of bristlemouths (genus Sigmops) and several species of scaleless dragonfish. We have caught some of these species in our other stations, as the bottom nets continue to catch animals as they are hauled back to the surface, but not in such good condition.
There are many confusing terms used for different groups of animals in the deep sea. As discussed in earlier diary entries, the mid-water animals at depths of around 200 to 800 metres migrate up into shallower waters every night to feed. These are known as “vertical migrations” and happen all over the world on a massive scale every night. The animals from these depths are known as “mesopelagic”, meaning “middle” (as in mid-depth) and “free-swimming”. The animals in yesterday’s mid-water trawl live much deeper (>1000 m) and do not make the treks up and down every night. These animals are known as “bathypelagic”, meaning “deep” and “free-swimming”. They hang mid-water, typically a long way from the seafloor. Other groups of animals also hang in the water but close to the seafloor, feeding on animals associated with the seafloor. These are known as “benthopelagic”, meaning “bottom” and “free-swimming” (the term “demersal” is also used to describe such animals). The animals that live on (or in) the seafloor are known as “benthic”, meaning “bottom-living”. Those that live on the surface are called “epifauna”, those that are buried in the sand or mud are known as “infauna”. Enough terms!
Bruce Barker from CSIRO has just developed another series of drop camera films taken yesterday on the top of a seamount at around 750 m deep. Most of the shots were of barren rocky seabed. One shot however had snapped three rattail fishes over a rippled seafloor. It is difficult to tell if the ripples are in sand or part of the rocky seabed. Most people think that there is no water movement in the deep sea, that it is a still, static sink. Deep-sea currents do occur, strong enough in areas to form regular ripples in the sand or mud. It is these currents that carry the smells of food to foraging animals. These are also the currents that strike the seamounts sticking up out of the deep-sea plains to form eddies that concentrate nutrients and result in the rich communities found on seamounts.
As we steam for Wellington, it is appropriate to describe the driving force of the Tangaroa, its engine room and the engineers, John and Geoff, that keep the system running smoothly. The Tangaroa has a single large 3,000 kW diesel engine. It has eight cylinders with each huge piston being 32 cm across. When under way, the electricity for the ship is produced by a large alternator that runs off the drive shaft. Separate refrigerator plants power the large onboard freezers used on this trip to store specimens. The Tangaroa makes its own fresh water using two “evaporators”, which heat seawater under a vacuum so that it boils at around 50 °C. The steam is then drawn off and cooled to make pure water. These units can produce 16 tonnes of fresh water per day.
People have spent most of today on the big clean up and preparation for unloading all the specimens collected over the past four weeks. We should hit Wellington tomorrow morning. Everybody is keen to see land.
Day 29: 7 June 2003
By Mark Norman, Museum Victoria
Moderate swell (2-3 m), 20 knot SW wind, 16 °C
Well, at 7 am this morning we woke to find a beautiful sunny day and the Tangaroa steaming inside Cook Strait in the last few miles to Wellington.
It is the end of an amazing voyage. It has been a ground-breaking survey – the most complex and multi-faceted marine research expedition ever conducted in Australasia. This unique trans-Tasman collaboration involved diverse organizations and more than 20 scientists from Australia, New Zealand, France and the USA. Their combined expertise covered geology, seafloor mapping, water characteristics and marine life of the deep sea.
The statistics for the NORFANZ voyage are impressive. The ship has covered more than 5000 nautical miles, sampled 14 seamount systems and 168 stations (almost twice the planned number of stations), down to a depth of 2000 metres. A huge diversity of animals was encountered, in every shape and size: from blobfish to prickly sharks, and miniature brittle stars to giant sea spiders. The adaptations of these animals to their dark cold homes were just as diverse.
A total of over 500 fish species and 1300 invertebrate species were sampled. Many species new to science were recognised including new sharks and rays, redfish, rattails and a range of invertebrates. More than 100 species could not be recognised and may yet constitute new species. The final tallies are likely to rise further, once the appropriate experts examine all the material in detail. One of the regular themes of this voyage was the discovery of animals rarely caught in the past. These included the Ballina Angelfish, the Leopard Chimaera, several anglerfish species and various invertebrates such as deep-sea Sponge Shrimps.
The technological revolutions on this trip were the accuracy of the seafloor mapping and the generation of the onboard species reference folders. The detailed maps generated by multibeam scanning made it possible to place the nets precisely. Without these maps we would have snagged, damaged or lost most of our gear. The four fat fish folders and 11 invertebrate reference folders were invaluable in getting an immediate handle on the biodiversity encountered on this voyage. This enabled preliminary sorting and much more targeted distribution of the material on return to Wellington. The onboard digital photography captured fresh animal colours and form before preservation, a first for many of the species encountered. The sophisticated onboard databasing was also excellent for recording all aspects of voyage, station and specimen data.
Where does all this stuff go now? Collected material is now being distributed to the various research collections and world experts for further detailed examination. The ensuing analyses will allow assessments of the composition, diversity, unique nature and isolation of these amazing deep-sea and seamount communities. This material will be the subject of detailed research for years to come.
As this is the last entry I’d like to finish by thanking all the people that helped me so much with production of this daily diary, in particular Andrew Stewart, Bernard Seret, Karen Gowlett-Holmes, Martin Gomon, Tomio Iwamoto, Peter Davie, Penny Berentz, Tim O’Hara, Rick Webber, Ken Graham and all the subjects of individual stories in the diary entries. It has been fantastic to work with such an experienced, knowledgeable and enthusiastic group of people. I’d also like to thank the captain, Andrew Leachman, and all his wonderful crew for making the voyage such a success. We wouldn’t have caught a single animal without them. Thanks also to all the team at National Oceans Office, particularly Katrina Haig and Alicja Mosbauer. Most of all I’d like to thank Karen Zipkas for all her encouragement and support.
It is important to stress that the NORFANZ voyage has only skimmed the surface of the rich diversity of marine life found in the deep waters between Australia and New Zealand. There is still so much to learn.